The present invention relates to a golf club, and more particularly relates to improvements in a joint structure between a shaft and hosel of a wood- or iron- type golf club.
In a typical construction of a shaft/hosel joint of a conventional golf club, a shaft is fixed along it lower tip to a main body hosel within a shaft hole formed in the latter via an intermediate bond layer. More specifically, a main body of a golf club is provided at one squeezed or tapered end with a tubular hosel defining a shaft hole which extend upwards when the golf club is held in position. The tapered lower tip of a shaft is inserted into the shaft hole in the hosel and the shaft tip is fixed to the hosel via an intermediate bond layer within the shaft hole. Near the upper end of the hosel, the shaft/hosel joint is fortified by an embracing conical, tubular protector generally made of plastics.
In the case of such a conventional shaft/hosel structure, undesirable stress concentration is apt to occur around the border between the hosel and the protector due to impact at shooting balls. Buckling and/or compressire destruction accruing from such stress concentration often causes dangerous breakage of the shaft at the very moment of shooting balls. In particular in the case of a so-called short-neck type golf club including a relatlvely short hosel, poor holding of the shaft by the hosel tends to cause such breakage of the shaft due to impact generated by shooting balls.
In addition, the area of contact between a hosel and a shaft is rather small in the case of such a short-neck type golf club and poor holding by such a reduced area of contact allows easy destruction of the intermediate bond layer, which tends to dangerous separation of the shaft from the hosel when the former is swung for shooting balls.